| 摘要 |
An apparatus for preventing counterfeiting and alteration according to the present invention includes a magnetic changeable substance carrier part containing a magnetic changeable substance to vary reflected or transmitted light rays as an applied magnetic field is varied; a magnetic field generation part for generating a magnetic field applied to the magnetic changeable substance; and a moveable part for varying at least one of the intensity, direction and pattern of the magnetic field applied to the magnetic changeable substance according to an externally applied stimulus so as to change the appearance of the magnetic changeable substance. |
